The main difference between the two engines is that The Bat!'s does not use any outside code. Thus
the internal implementation will run on older Windows systems (like
Win9x or NT 3.51). The disadvantage is a lack of flexibility: when
it comes to using different third-party algorithms, storage media,
or devices that perform certain operations at a hardware level, you
will need to use the CryptoAPI engine, but it may work differently
or with some limitations under different versions of Microsoft
Windows.